Re: Hydrogen economy will never exist

From: daestrom (daestrom_at_NO_SPAM_HEREtwcny.rr.com)
Date: 07/04/04 

Date: Sun, 04 Jul 2004 17:28:53 GMT

"william mook" <william.mook@mokindustries.com> wrote in message
news:407c5321.0407040717.36982363@posting.google.com...
> Don Lancaster <don@tinaja.com> wrote in message
news:<40E6FC26.71C7FD5C@tinaja.com>...
>
> > There is NO WAY IN HELL that you can produce hydrogen from pv for less
> > than the ultimate cost of a synchronous inverter.
>
> Look, silicon costs about $1 per square inch. That's 15.5 cents per
> square centimeter. Operating at 120x solar intensity and 20%
> conversion efficiency that's 2 watts electrical per 15.5 cents -less
> than a dime a watt.
>
> Now add in your concentrator cost. Well, 1 square meter of aluminized
> PET film stabilized by structural EPS (think of a bicycle helmet)
> costs about $4.00 - that intercepts about 200 watts electrical on a
> clear day - another 2 cents per watt electrical. Still under a dime.
>
> So we have precision optics and PV for less than a dime a watt.
>
> Okay, you do have to cool the thing and point it. That gets you up to
> 30 cents per watt...
>

Hmmm cooling....

Could this be used as a low-grade source of heat? After all, much of the
energy used in a home is just this type. Water heating and space heating
from this cooling system would provide another 'avoided cost' by replacing
the conventional forms of energy used for such purposes.

One would have to maintain your original cooling sink for those times when
water/space heating isn't needed, but that is in your original costs. The
extra cost to circulate some coolant into the home on demand would seem
relatively small.

If it *does* make sense (thermodynamically and economically) to go forward
with water/space heating, then a separate question might be if it makes
sense (again, both thermo and economic) to add some modest thermal energy
storage.

How much heat does your cooling system currently have to reject when
operating and at what temperature? (I would make it at about 4 watts per
watt of electric output) This additional possibility for using this
rejected heat for another purpose has some interesting possibilities.

daestrom

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